Wireless communication has become common in all aspects of life today, whether it be a wireless home or office network, so-called “hotspot” networks at local cafes, fast food chains or hotels, or even citywide implementations of WiFi technologies. The aim of this wireless push in society is to provide accessibility to information and to increase the productivity that society as a whole has enjoyed through the wide acceptance and utilization of computer networks and especially the Internet.
Simply installing wireless antenna on a node and then transmitting uncoordinated communications would result in collision of data, interference and a significant transmission delay. Specifically, by transmitting uncoordinated data, the airwaves would be flooded with a plurality of messages, which would result in a jamming of the radio waves, as the radio bandwidth is limited. As such, the nodes would interfere with each other's transmission and compete with each other for radio bandwidth for transmission. Further, all messages would propagate in all directions without any consideration of a desired transmission direction.
These problems become more apparent in ad-hoc networks and in networks where the nodes are moving, especially if the nodes are moving vehicles that move at high speeds. Grouping of mobile nodes can support more efficient network management among a specific set of nodes. However, the mobility and lack of inherent relationships make a priori configuration of vehicles into groups problematic. Information such as traffic advisories, Amber alerts, weather advisories, etc., need to be relayed quickly to the vehicles, without delay and interference.
Notably, all information that is necessary for setting up safety communications must be exchanged in near real-time among moving vehicles, and vehicles in the groups must configure themselves in near real-time so that safety communication can take place. The mobility of vehicles implies frequent change of neighbors or vehicle groups, and poses difficulties of using support-servers (for mobility, address, name, media session) within vehicle groups. These key differences make existing tactical ad-hoc networking technologies not directly applicable to vehicle groups for safety communications.
The '047 Application describes a method to organize groups of moving vehicles into a local peer group, selecting one moving vehicle as a group header or leader, maintaining the local peer group using the group header, and generating local routing information. The moving vehicles are adapted for uni-cast and multicast routing.
A moving vehicle cannot simultaneously transmit on and receive through the same channel. Prior to data transmission a channel must be selected. The '047 Application describes that the group header can select the channels for the local peer group. In an embodiment, the '047 Application describes that the channels are selected in a channel-alternate forwarding manner. In another embodiment, '047 Application describes that the transmission and reception channels will be assigned in a double channel alternate manner.
However, the method does not account for local channel availability and movement of the nodes.